Flat retroreflectors

Patent metadata

Field	Value
Publication number	US-9453947-B2
Application number	US-201414558201-A
Country	US
Kind code	B2
Filing date	Dec 2, 2014
Priority date	Dec 3, 2013
Publication date	Sep 27, 2016
Grant date	Sep 27, 2016

Abstract

A retroreflector device is described, which includes a lens component operable for focusing radiation, which is incident thereto at an angle of incidence. The retroreflector also includes a mirror component operable for reflecting the radiation focused by the lens component back along the angle of incidence. The lens component and/or the mirror component includes a quasi-periodic array of elements, each of which comprises a dimension smaller than a wavelength of the radiation.

First claim

What is claimed is:

1. A retroreflector device, comprising:
a lens component operable for focusing radiation, which is incident thereto at an angle of incidence; and
a mirror component operable for reflecting the radiation focused by the lens component back along the angle of incidence,
wherein one or more of the lens component or the mirror component comprises a quasi-periodic array of elements, each of which comprises a dimension smaller than a wavelength of the radiation.

2. The retroreflector device as described in claim 1 , further comprising a modulator component integrated therewith.

3. The retroreflector device as described in claim 2 wherein the modulator component is operable for performing at least one of a transmitter related functionality or a transceiver related functionality.

4. The retroreflector device as described in claim 2 wherein the modulator component is disposed externally in relation to the retroreflector device with which it is integrated.

5. The retroreflector device as described in claim 2 wherein the modulator component is disposed internally in relation to the retroreflector device with which it is integrated.

6. The retroreflector device as recited in claim 2 wherein the modulator component is integrated therewith monolithically.

7. The retroreflector device as recited in claim 2 wherein the modulator component is integrated therewith using a hybrid technique.

8. The retroreflector device as recited in claim 2 wherein the modulator component is operable for performing a modulation function, which comprises one or more of:
an amplitude related modulation functionality;
a phase related modulation functionality; or
a polarization related modulation functionality.

9. The retroreflector device as recited in claim 1 wherein one or more of the lens component or the mirror component are disposed on a semiconductor substrate.

10. An optical apparatus, comprising:
a retroreflector device disposed on a semiconductor substrate, the retroreflector device comprising:
a lens component operable for focusing radiation, which is incident thereto at an angle of incidence;
a mirror component operable for reflecting the radiation focused by the lens component back along the angle of incidence,
wherein one or more of the lens component or the mirror component comprises a quasi-periodic array of elements, each of which comprises a dimension smaller than a wavelength of the radiation within the operationally efficient wavelength range;
a spacer component, which is transparent over the operationally efficient wavelength range and disposed between the lens component and the mirror component;
a material, which has a low refractive index in relation to the operationally efficient wavelength range and is disposed over the semiconductor substrate beneath the mirror component in relation to the lens component; and

an optical modulator transceiver or transmitter device integrated with the retroreflector device and operable over the operationally efficient wavelength range for performing one or more of amplitude, phase, or polarization related modulation of the incident radiation.

11. The optical apparatus as recited in claim 10 wherein the device is operable optically over a range of wavelengths corresponding to an infrared spectral range.

12. The optical apparatus as recited in claim 11 wherein:
the substrate material comprises silicon; and
the low refractive index material disposed thereon beneath the mirror component comprises silicon dioxide.

13. The optical apparatus as recited in claim 10 wherein the operationally efficient wavelength range relates to a characteristic of one or more of the lens component or the mirror component.

14. The optical apparatus as recited in claim 13 wherein the characteristic of the one or more of the lens component or the mirror component relates to a parameter associated with the quasi-periodic array of thereof.

15. The optical apparatus as recited in claim 14 wherein the parameter associated with the quasi-periodic array comprises one or more of:
at least one of a size or a shape of a lattice feature of the quasi-periodic array; or
at least one of a size or a shape of one or more of a plurality of unit elements, which comprise the lattice.

16. The optical apparatus as recited in claim 10 wherein the retroreflector is optically operable over one or more frequency ranges of the electromagnetic spectrum.

17. The optical apparatus as recited in claim 16 wherein the one or more frequency ranges correspond to at least one of a radio, a microwave, a Terahertz, an infrared, a visible and/or an ultraviolet, or an x-ray related wavelength.

18. A method of fabricating an optical retroreflector device, the method comprising:
disposing a lens component on a semiconductor substrate, wherein the lens component is operable for focusing radiation, which is incident thereto at an angle of incidence; and
disposing a mirror component on the semiconductor substrate, herein the mirror component is operable for reflecting the radiation focused by the lens component back along the angle of incidence,
wherein one or more of the disposing the lens component or the disposing the mirror component comprises disposing a quasi-periodic array of elements, each of which comprises a dimension smaller than a wavelength of the radiation,
wherein an optical operating range of the retroreflector device relates to a parameter characterizing one or more of the lens component or the mirror component, and
wherein the parameter of the one or more of the lens component or the mirror component relates to one or more of:
at least one of a size or a shape of a lattice associated with the one or more of the lens component or the mirror component; or
at least one of a size or a shape of each of a plurality of unit elements, which comprise the lattice.

19. The method as recited in claim 18 , further comprising one or more of:
disposing an optically transparent spacer component between the lens component and the mirror component on the semiconductor substrate; or
integrating an optical modulator component with the retroreflector device.

Assignees

• California Inst Of Techn

Inventors

• Arbabi Amir
• Faraon Andrei

Classifications

• H04B10/501

  Structural aspects · CPC title

• G02B5/136

  plural reflecting elements forming part of a unitary body (G02B5/124 takes precedence) · CPC title

• G02B5/13 Primary

  plural curved refracting elements forming part of a unitary body · CPC title

• H04B10/40

  Transceivers · CPC title

• H04B10/516

  Details of coding or modulation · CPC title